1. Field of the Invention
This invention relates to a method of manufacturing a floating magnetic head device used for a hard disk drive unit or a floppy disk drive unit.
2. Description of the Related Art
The floating magnetic head device used for a hard disk drive unit for recording or reproducing information into or from a hard disk has a magnetic head element for recording and reproducing of information loaded on a slider, and has the slider supported by a suspension composed of a blade spring. The slider is mounted on an actuator arm rotating in the radial direction of the hard disk.
The slider is caused to contact the surface of the hard disk by downward spring load applied from the suspension when the hard disk is not rotated. When the hard disk is rotated, the slider is caused to float by upward lift due to an air current generated by the rotation of the hard disk. As the downward spring load is applied to the slider from the suspension, the slider having the magnetic head element loaded thereon floats in running with a slider floating distance determined by a balance of the upward lift and the downward spring load. The slider rubs the hard disk immediately before actuation and termination of operation.
In the floating magnetic head device as described above, protrusions and grooves are provided on the hard disk facing surface of the slider to shorten the rubbing time with the hard disk and to improve durability, and the upward lift applied to the slider is adjusted to adjust the slider floating distance. For instance, rail processing is carried out on the hard disk facing surface of the slider to form slider rails as substantially rectangular protrusions thereon. The hard disk facing surface of the slider rail is used as an air bearing surface to receive the air current generated on the hard disk surface. A groove called an air groove which the air current enters is provided between the slider rails, to adjust the slider floating distance. The projections and groove are formed by mechanical processing.
However, as a reduction in size of the hard disk drive unit has been recently required, a reduction in size of the slider constituting the floating magnetic head device is required. Consequently, the above-mentioned mechanical processing of the slider is becoming more difficult on the basis of precision.
Also, as a higher recording density of the hard disk drive unit has been recently required, a lower floating distance and stability of the slider floating distance of the floating magnetic head device are required. However, the lower floating distance and stability of the slider floating distance are difficult in the floating magnetic head device using the slider having slider rails as substantially rectangular protrusions provided on the hard disk facing surface thereof as described above.
Thus, floating magnetic head devices using various sliders having slider rails and air bearing surfaces which are improved in shape are proposed. However, these sliders have slider rails which are not simple in shape, and are more difficult to process by mechanical processing. As methods of processing such sliders, vacuum etching such as ion milling, and powder beam processing using fine abrasive grains, as disclosed in the JP Laid-Open (KOKAI) Publication No.3-149184, are proposed. However, mass production of the sliders processed by the above-mentioned ion milling or the powder beam processing is difficult. Therefore, the floating magnetic head device using such sliders is considered to be impractical.